The present invention is directed generally to a circuit arrangement and, in particular to a circuit arrangement provided with an up-converter which comprises at least an inductive means and switching device a, a capacitive device which in the operational state of the circuit arrangement is periodically charged with a charging current in dependence on periodic switching of the switching device by a drive circuit, the switching device means being switched to the conducting state periodically for a substantially constant time t.sub.on.
A circuit arrangement of the kind mentioned in the opening paragraph is known from DE-OS 26 52 275 and may effectively serve, for example, for operating a discharge lamp in conjunction with current stabilization device. By choosing the moment at which the switching device is switched to the conducting state so as to coincide with the moment the current through the inductive device becomes zero, it is possible to ensure that the load current drawn from the supply source by the circuit arrangement, in the case of operation of the circuit arrangement on a usual sinusoidal AC voltage supply source, is also sinusoidal by good approximation. In general, the current drawn from the supply source will assume a shape corresponding by good approximation to that of the supply voltage during such operation of the known circuit arrangement. A further advantage of the known circuit arrangement is that switching-on of the switching device takes place at the moment at which no current is flowing, so that switching losses are limited. Practical realization, however, leads to a comparatively high degree of intricacy of the drive circuit.